help! shugart 801

From: Don Maslin <donm_at_cts.com>
Date: Tue Jul 22 18:14:00 2003

On Tue, 22 Jul 2003, Joe wrote:

> At 09:26 AM 7/22/03 -0700, you wrote:
> >>From: Joe <rigdonj_at_cfl.rr.com>
> >>
> >> I have several systems that use Shugart 800-1 SS 8" disk drives. I've
> >>got several defective drives plus I've been wanting some spares. Last week
> >>I picked up 10 Shugart model 801 SS drives. Today I tried to use them on
> >>the same systems but I can't make them work. I've set all the jumpers and
> >>straps exactly the same as in the 800-1 drives but the 801s aren't working.
> >>The system knows the drive is there and detects the disk being in place and
> >>rotating and that the drive door closed but the drive never gets the head
> >>load signal. I'm using the same system, cables, power supply, etc with both
> >>drives so the only difference is the drives themselves. I've tried a couple
> >>of 801s and gotten exactly the same results with all of them so I don't
> >>think that it due to a drive failure. Anybody have any experience with
> >>these or have a good idea of what's wrong?
> >>
> >> Joe
> >>
> >
> >
> >Hi Joe
> > You do know that some of the drives have data separators.
> >I forget which numbers have this and which don't. I don't recall
> >if the 800-1's had them or not. If you are using these for
> >M2FM, is seems that I remember that the bandwidth was slightly
> >increase on these drives. As I recall, there was a capacitor
> >change in the pre-amps.
> > Those are the only things I can think of.
> >Dwight
> >
>
> You may be right but the head isn't even loading so I'm not even getting
> that far. I have a Shugart 800/801 manual but it's vague about the
> differences between the two. But IIRC the 801 is designed to handle hard
> sectored disk and the 800 doesn't. I'm wondering if the index pulse
> detection circuit is different and may be causing a not ready condition or
> something similar. (Yes I know I can check it with a logic probe but I
> didn't have one where the machines are located so I havne't done that yet.)
>
> Joe

Joe, the 800 series OEM manual has a brief table entitled Model
Differences. It is copied below:

800-1 Soft Sectored with an FM (single density) data separator.
800-2 Spft Sectored without data separator.
800-4 Mechanics only (No PCB)
801 Hard Sectored with an FM (single density) data separator
        and sector separator.

NOTE:
        To convert a 801 to a 800 move the shorting plug from the
        801 position to the 800 position. A 800 cannot be
        converted to a 801.

                                                - don
Received on Tue Jul 22 2003 - 18:14:00 BST